Manufacture of hollow ingots and tubes



Nov. 5, 1935.

E. F. JONES MANUFAGTURE OF HOLLOW INGOTS AND TUBESl 4 Sheets-Sheet 1Filed Deo. 6, 1955 Nov. 5, 1935.

E. F, JONES MANUFACTURE OF HOLLOW INGOTS AND TUBES Filed Dec. e, 1953 4Sheets-Sheet 2 NOV. 5, 1935. E, F, JONES 2,019,820

MANUFACTURE OF' HOLLOW INGOTS AND TUBES Filed Dec. 6, 1955 4Sheets-Sheet 3 Nov. 5, 1935. E, F. JONES MANUFACTURE of* HOLLOW INGoTsAND TUBES 4 Sheets-Sheet 44 Filed Dec. 6, 1955.

1 I l I I l VPatented Nov. l5, 1935- IVIANEJFAC'lIURE 0F HOLLOW INGOTSAND TUBES Ernest Fraser Jones, London, England, assigner toFraser-.iones Limited, Johannesburg, Transvaal Province, Union of SouthAfrica Application December 6, 1933, Serial No. 701,216 In Great BritainDecember 21, 1932 s Claims.

This invention comprises improvements in or relating to the manufactureof hollow ingots and v tubes.

1,938,257, dated December 5, 1933, there is de- 5 scribed a processorproducing hollow ingots for the manufacture of metal tubes in which aplunger is introduced axially into a mould partially lled with moltenmetal so as to press the metal tothe form of a hollow ingot, and the lsurface of lthe metal between the sides of the y plunger and the wallsof the mould is subjected to pressure applied at is upper surface duringsolidication. The purpose ofthe application of pressure around theannular upper surface of 15 the ingot is to compress the metal andprevent y the formation of pipes, the pressure-applying member followingthe metal downwards into the mould as the latter contracts on cooling.Sound ingots are thereby ensured. 20 In this process it is necessary towithdraw the plunger as soon as possible after solidiiication of themolten metal and considerable force i is necessary to eiiectA therequired withdrawal.

The present invention comprises in apparatus 25 for the manufacture ofhollow ingots the combination of an ingot mould open at the tolli,v aplunger, means for supporting the plunger above the mould and forlowering it thereinto, a sleeve to surround the plunger and means forlowering 30 the sleeve into the mould so as to press on to metal thereinand a releasable mould-support for supporting the mould against downwardpressure of the plunger and/or sleeve, such that when released the mouldis capable of downward 35 movement relatively to the plunger under theiniluence of pressure on the sleeve. In use of this apparatus when themetal has solidified in the mould the support is released so that themould with the shaped metal contained therein is 40 forced downwardlyoff the end of the plunger by the pressure of the annular sleeve-member.By this means release of the plunger is eiected by the application ofpressure in the same direction and by the same means 'as that which com-45 presses the metal in the mould and the plunger is freed so that itssubsequent retraction becomes easy.

Preferably the vplunger is tapered and the` mould support is 4such thatdownward movement 50 of the mould may take place gradually duringsolidication of the ingot. This allows the metal to contract insolidifying and not only tendsvto free the plunger but also to preventinternal cracking of the ingot. 55 The mould-support may comprise anhydraulic In prior United States Patent No.k

cylinder and ram so that the mould is supported by operating the ram andreleased by releasing hydraulic pressure therefrom.

The downward pressureof the annular member may be likewise effected byhydraulic plungers 5 and the oil pressure for supporting the mould andfor operating the annular pressure member may be derived from the samesource. The construction of the hydraulic mechanism for operating theannular pressure member may be similar to that described in co-pendingUnited States application No. 669,046, filedMay 2, 1933.

Oil pressure is preferred to water pressure for working the hydraulicplungers because should any leakage of oil take place this is lesslikely than water to lead to explosions ii it comes in contact withheated steel. E

Preferably the mould is subjected during the setting of the metal tostrong vibration. The purpose of the vibration is to cause the metal toassume a more compact form and to avoid the production of pipes.

' The vibration may be applied either by a rapid movement of the mould(for example in a vertical or axial direction) or it may be applied byeffecting a hammering action upon the exterior of the mould itself.

If desired the Vibration may be maintained. for example by hammeringupon the exterior of the mould, during the period in which the plungeris freed from the molten metal after the metal has set by downwardpressure of an annular sleeve surrounding the plunger upon the, top ofthe metal, the mould being allowed to descend during this operation.

The hammering action upon the exterior of the mould may be effected byapplying an automatic hammer thereto, such, for example, as a pneumatichammer, and the hammer may either be incorporated in the design of theapparatus or may be constituted by a separate pneumatic hammer manuallyapplied.

The following is -a description by way of eX- ample of one form of theapparatus in accordance with the invention, as applied to an ingotcasting machine having a plurality of moulds arranged upon an endlessconveyor chain.

In the drawings:- Figure 1 is an elevation of part of the machine;

Figure 2 is a cross section on the line 2 2 of Figure 1 looking in thedirection of the arrows; Figure 3 is a detail of certain of the partsshown in Figure 2;

Figure 4 is a view looking in the direction oi' 55 y the arrows 4-4 ofFigure 2, of the exterior of those parts which are co-axial with thecentre line of Figure 2; and

Figure 5 is a diagrammatic view of a modied construction.

Referring to Figure l, the machine comprises a framework consisting ofhorizontal joists II, I2 spaced apart towards their ends by verticalplates I3, I4 and supporting between the plates spindles I5, I6 whichcarry sprocket wheels I1, I8, one at one end and the other at the otherend of the framework. A chain conveyor formed of links I 9 pivotedtogether by hinge pins 20 extends around the sprocket wheels I1, I8 andthe upper length of the conveyor runs along rails 2|, 22 supported onthe horizontal side members of the framework. The rails 2l, 22 form arunway and the hinge pins 20 of the conveyor carryk rollers 25 which runalong the rails. Mounted upon the links I9 there are a series of mouldcarriers 23 which contain moulds 24, one mould being allocated to eachlink of the conveyor.

Means are provided for moving the conveyor forward step by step by anamount equal to the pitch of the links of the chain. This feeding meansdoesnot in itself comprise any part of the present invention but it isindicated in the drawings as consisting of a crank member 26 mounted toturn about the spindle I6 and carrying at its free end a pawl 21 toengage a ratchet wheel 28`xed to the spindle I6. The free end 30 is sorelated to the radius of the crank meminto position beneath the plunger.

ber 26 that a complete rotation of the crankpin 30 will swing the crankmember 26 to and v fro through an arc slightly exceeding Rotation of thespur wheel 3l will, therefore, produce an intermittent advance movementof the sprocket I1 through an arc of 60 for each rotation of the spurwheel, the advance movement being alternated with a period of rest. Thespur wheel 3I is driven through suitable reduction gearing from anelectric motor.

Aboutmidwayalong the length of the conveyor there is mounted a frameworkconsisting of uprights 32, 33 united by cross members 34, 35 and in theupper portion of the framework means are mounted, not shown in thedrawings, for raising and lowering a plunger 36 so that it may enter themoulds below or be withdrawn therefrom. The conveyor and the operatingmechanism therefor areso designed and arranged as to advance the mouldsstep by step into positions in which each of them in turn comesapproximately centrally beneath the plunger 36. Means hereinafterdescribed are provided to ensure exact centering before the plungerdescends and the plunger-operating mechanism is such as to raise it fromthe mould after the metal has set in the mould and before the conveyorexecutes afresh advance movement to bring a new mould Means for raisingand lowering the plunger are not herein described .in detail as they donot in themselves form part of the present invention and they may beconstructed in any suitable way.

Preferably means are provided for using several plimgers. seriatim so asto avoid overheating any one plunger by too frequent immersion in moltenmetal, but such means form no part of the presentA invention.

As will be observed from Figures 2 4, the chain links I9 are constitutedby rectangular plateshaped castings. These fit together like a hinge atthe joints of the linksand the pins 20 constitute hinge-pins. The moulds24 are substantially circular in plan and they comprise a cylin- 5drical bottom portion 40 which passes through an aperture in the linksI9 and is provided with a head below the link, the dimensions being suchthat the member 4I! can slide up and down through the link to a limitedextent. The mould is held from turning relatively to the conveyor bymeans of a locking plate 4I bolted to the upper side of the mouldcarrier 23 and provided' with a projecting portion which enters a notch42 in the side of the mould. The mould may be removed from the carrierby unscrewing the locking plate 4I and unscrewing the sliding member 40from the underside of the mould. This construction permits of changingthe moulds in a given machine so that various sizes of moulds can beemployed in accordance with the size of ingot required. In Figures 2 and3 the ingot itself is shown at 43 and it will be observed that thebottom of the mould is stopped by a conical plug 44 which overlies acentral aperture 45 extending right through the mould and flaredoutwardly at itsbottom end. Figure 3 shows the parts in the positionwhich they assume when the metal has been poured, the plunger loweredinto place and the ingot is solidifying. Figure 2 3i! shows the parts inthe position which they as sume after withdrawal of the plunger when theconveyor is about to move forward a further step in readiness to bring anew mould beneath the plunger. It will be lmderstood that means are 35provided to feed molten metal to the moulds before reaching the plungingposition. Such means would comprise a suitable ladle and means formeasuring the amount of metal poured into the moulds but they are notshown in the Ydrawings 40 as they constitute no part of the presentinvention.

Below the mould 24 and the rails 2l, 22 there is a erom member 46 whichextends from side to side of the machine, being Supported upon the 45uprights 32, 33. This carries a cylinder 41 for an hydraulic ram 4llocated coeaxial with the mould 24 and the plunger 36. 'I'he upper endof the ram 43 carries a mould-lifting table 49 and a centralizing pin 56upstanding from the table. 5;) The pin SII is designed to enter theaperture 45A in the bottom of the mould and thereby. to bring the mouldexactly central beneath the plunger 36. The table 49 constitutes amould-support and when the ram 4I rises it lifts the mould a short 55distance towards the plunger, causing it to slide throughl the link I3and mould-support 23 as already described. 'I'here is an oil pressuresupply pipe 5I to the cylinder 41 and means are provided to connect thisto an oil pressure supc3 ply, together with a control cock so designedthat either pressure may be admitted to the cylinder, oil containedtherein may be locked there against outflow, or in another position ofthe cock may be exhausted from the cylinder.

A tail rod 52 projects through the bottom of the cylinder, leakage beingprevented by a stuifing gland 53. The tail rod 52 carries a block 54.The block 54 has pins 55 projecting from it coaxial with one another onopposite sides and the pins enter slots in a forked lever 56 pivoted at51 on a cross-bar supported from the frame of the machine. The lever 66projects beyond the pivot point to a pin 56 by which it is connected tolinks 53. Two linksil are provided which lie -armli one before the otherin Figure 4 of the drawings and they are connected to two pull-rods iunited together at the top by a crosshead 6|, the centre of which is'secured to the upper end of a ram 62 working in a return cylinder 33. Byapplying hydraulic pressure to the return cylinder 33 the ram 62 israised and by lifting the pin 54 of the lever 56 it will serve to drawdown the block 54, tail rod 52 and ram 48. This ensures positivelowering of the ram when pressure in the cylinder All is released. Thecylinder 63 will normally have a constant hydraulic pressure appliedthereto, but as it is much smaller than the cylinder 41 its ehect willbe overbalanced by the latter whenever pressure is applied in the largercylinder. It will be observed that the bottom sliding portion 4i)secured to the mould 24 is notched out as shown at 64, Figure 2, topermit the centering pin 50 of the mould-supporting table to lie closeto the bottom of the mould without interfering with the .movements ofthe conveyor when the pin is in its lowered position.

A bracket 65 is formed on the cross member 34 of the framework so as tooverlle one side of the link i9 where the mould-support is located andto prevent the mould-support lifting the link when it rises to engagethe mould. The mould and mould-support are shown in the lifted positionin Figure 3.

Above the'mould in Figure 2 is shown a sleeve 10 removably mounted in acrosshead 1I which extends across the machine from side to side andcarries at its two ends upper rams 12, 13 and lower rams 14, 15. Theupper rams 12, 13 enter sleeve-lowering cylinders 13 and the lower rams14, 15 enter sleeve-raising cylinders 11. The sleeve 10 is co-axial withthe plunger 36 and of such a size that'it can enter the upper ends ofthe moulds 24 below. The mouthsof the moulds are flared somewhat tofacilitate entry of the sleeve and to allow the sleeve to centre theupper-end of each mould as lit enters the same. It will readily beunderstood that by appropriate oil supply means and controllingarrangements pressure may be admitted to the upper cylinders 13 whendesired to cause the sleeveto enter the mould. These cylinders arelarger than the lower cylinders 11 and if a. constant oll pressure ismaintained in the latter then the sleeve will be raised as soon aspressure is liberated from the upper cylinders 16. When the pressure isapplied in the cylinders 16 the sleeve is lowered because the power ofthese cylinders overcomes the inferior force of the lower cylinders 11.The bore of the sleeve 10 is such as to receive and centre the plunger36 while leaving it free to descend through the sleeve and enter themolten metal in the mould 24 below.

The block 54 on the tail rod 52 of the ram 48 is formed with a cam faceIl on one side and this cam face co-operates with a cam lever 8|(Figure 1) pivoted on an axis at I2 extending transversely across themachine and connected to-a connecting rod 33. The connecting rod 33extends to a. pin 84 on a crank arm 35 pivoted freely about the spindlel5 of the sprocket I3 which supports the conveyor at the opposite endfrom the driving sprocket I1. Fast upon the spindle I5 is a ratchetwheel and the crank carries a pawl I1 to engage with the ratchet wheel.The cam face il is so located that during the initial movement of theram 48 in an upward direction and before the centering pin 50 enters themould aperture 45, tension is applied to the connecting rod 83 and thesprocket i8 is thereby moved slightly in an anti-clockwise direction asviewed in Figure 1 of the drawings, thus relieving the conveyor links I9of any tension under which they might otherwise lie as a result of thefeeding movement due to the 5 sprocket wheel l1. This relief of tensionof the links in the upper part of the conveyor enables the centering pin50 to centre the mould 24 easily.

In operation of the machine, when one of the moulds 24, lled with moltenmetal, has arrived beneath the plunger 36, oil under pressure is rstadmitted .to the cylinder 4lll thereby raising the ram 48. This afterinitially relieving the tension in the links of the conveyor as justdescribed centres the mould by the action of the pin 50 and thenl liftsthe mould into the position shown in Figure 3. Thereafter the sleeve 10is lowered a short distance into the mouth of the mould by admission ofa limited quantity of oil under pressure to the upper cylinders 16, thuscentering the upper end of the mould. The plunger 36 then descends andenters the molten metal which flows upwardly round the plunger as it isdisplaced thereby until it nearly lls the mould. The sleeve 10 is thenfurther lowered so as to press firmly on the upper annular surface ofthe molten metal and this pressure is maintained during solidication ofthe metal. During solidification of the metal a slight escape of oil isallowed from the cylinder 41, thereby allowing the mould to fallgradually and permitting the ingot tovcon'fract during solidiilcationaround the tapered portion of the plunger.

As soon as the metal is suiciently solidified to be able to retain itsshape, even if the plunger were withdrawn, oil, which up to this point,although escaping, had been held under pressure in the cylinder 41 isnow freely released from that cylinder and thus the mould-supportingtable 49 40 becomes free to descend fully. Pressure is still maintainedin the upper or sleeve-lowering cylinders 16 and as this pressure is nownolonger resisted by the mould-support 49 the sleeve is able to forcethe moulded ingot and the mould downwardly off the tapered lower portionof the plunger 36. The plunger 36 is restrained by its operatingmechanism from downward movement along with the ingot and thus theplunger is freed from the ingot and may be lifted readilyout of 50 theingot mould by its control mechanism.

By this-means the mechanism for raising and lowering the plunger may bemade much lighter than would be the case had the necessary force forfreeing the plunger from the ingot to be applied by the plunger-raisingmechanism itself.

If vibration is to be applied to the mould as already referred to, thismay be done during the settingof the ingot by applying a pneumatichammer to the side of the mould, maintaining the hammering if necessaryduring release of the plunger and its upward withdrawal.

As soon as the plunger is clear the pressure is released from the uppercylinders 16 and the sleeve 10 is thereby lifted clear of the mould in65 time to permit the next advance or feeding movement of the conveyor.It will, of course, be understood that the speed of the conveyor feedingmechanism must be designed to correspond with the time taken by the 7ingotsk to set in their moulds and the associated mechanisms to performtheir allotted operations.

Referring to Figure 5, this shows diagrammatically a. modifiedarrangement which may be employed when very narrow deep moulds are io beu used. iUnder these conditions it becomes difiicult to pour the moltenmetal to the bottom of the mould without touching the sides. If themetal touches the sides during pouring it becomes unduly cooled, whilethe mould becomes unevenly heated. Moreover, in a very deep mould thereis a tendency for the metal to splash4 as it is poured.

Accordingly, in Figure 5 the mould is constructed in three sections, ofwhich the bottom section 24 is similarly constructed and corresponds to`the moulds 24 already described.

'I'he upper sections |25, |26 each constitutes one-half of a verticallydivided top portion to the mould, and they are mounted on hydraulicplungers |21, |28 operated by cylinders |29, |30 at the vsides of themachine in'the same plane as the A another so that they meet above themould |24 and their lower faces |3|, |32 are arranged to ilt closelyagainst the upper faces |33 of the mould |24 while their internalvertical surfaces |34 constitute extensions of the inner walls of themould |24.

Thereafter entry of the sleeve and descent ofthe plunger |36 takes placeas hereinbefore described, the upper parts of the mould |25, |26 serveto receive the molten metal forced upward out of the lower section |24by the action of the plunger. As soon as the metal is set and the sleeve|10 and plunger |36 have been withdrawn the upper sections of the mould|25, |26 are withdrawn also and the lower part of the mould carries thenow-solidified ingot forward. It will be observed that the lower portionof the mould constitues a vessel into which it will be easy to pour themoltenmetal without danger of touchingthe sides during pouring. Afurther advantage of sub-dividing the mould as described is that theweight of the moving moulds upon the conveyor is reduced as comparedwith the weight which they would have were they constructed deep enoughto accommodate the full. height of the ingots and therefore the weightof the conveyor and moulds takenas a whole is reduced. As this weight(which is very great) has to be started and brought to restl at everystep of the conveyor the advantage of thus reducing its inertia andmomentum is considerable.

The control of the periods of and amount of admission of oil to thevarious cylinders is automatically effected by a control mechanism,such, for example, as thatdescribed in United States application No.669,046 hereinbefore referred to'.

I claim as my inventioml. In apparatus for the manufacture of hollowingots, the combination of a chainconveyor having a plurality of links,a plurality of moulds open atthe top mounted in series upon saidconveyor, each mould being slidably mounted for vertical movementrelatively to the links of the chain conveyor, means for feeding saidconveyor step by step to bring the moulds successively into operatingpositions, a plunger, means for supporting the plunger above 'anoperating position for theA moulds and for lowering it thereinto, avertically movable mould-support below the conveyor axially in line withthe plunger, and means to raise the mould-support towards the plungerfor each plunging operation.

ing a plurality of links, a plurality of moulds open s at the topmounted in upon said conveyor. means for feeding said conveyor step bystep to bring the moulds successively into operating positions, a.plunger, means for supporting the plunger above an operating positionfor the moulds and l0 for lowering it thereinto, a vertically movablemould-support below the conveyor axially in line with the plunger, meansto raise the mouldsupport towardsbthe plunger for each plungingoperation, a mould-centering device associated l5 with the mouldsupport, and means for insuring that the links of the chain conveyor areslack when the mould-support and centering device are operated. e

3. In apparatus for the manufacture of hollow ingots, the combination ofa chain conveyor having a plurality of links, a plurality of moulds openat the top mounted in series upon said conveyor, means for feeding saidconveyor step by step to bring the moulds successively into operatingpositions, a plunger, means for supporting the plunger above anoperating position for the moulds and for lowering it thereinto, avertically movable mould-support below the conveyor axially in line withthe plunger, means to raise the mouldsupport towards the plunger foreach plunging operation, a hydraulic ram located beneath said chainconveyor and carrying said mould support, sprockets supporting the endsof said chain conveyor, a pawl-and-ratchet device operatively'connectedto one of the sprockets so that upon actuation it tends to make thelinks of the chain conveyor beneath the plunger slack, and meansoperatively connecting the pawl-and-ratchet device to the hydraulic ramof the mould-support so as o to be actuated thereby.

4. In apparatus for the-manufacture of hollow ingots, the combination ofan ingot mould open at the top, a plunger, means for supporting theplunger above the mould and for lowering it thereinto, a sleeve tosurround the plunger, means for lowering the sleeve into the mould so asto press onto metal therein, and a releasable mouldsupport forsupporting the mould against downward pressure, such. that when releasedthe mould is capable of downward movement relatively to the plungerunder the influence of pressure on the sleeve, said mould beingconstructed in sections comprising a bottom section deep enough only tocontain the molten metal before depression of the plunger, and an uppersection or sections which can be superimposed over the bottom sec- Itionafter the pouring operation and before the 'plunger is lowered.

5. In apparatus for the lmanufacture ot hollow '60- 4ingots thecombination of a 'step-by-step conveyor, a series of moulds upon theconveyor sl as to be brought successively into moulding position, aplunger mounted' above the moulding position, means for lowering theplimger einto the 05 moulds in the moulding position and an additionalupper mould portion so located as to be superimposed above the mould inthe moulding 'position and to extendthe same vertically.

6. Apparatusasclaimedinclaim5,whereinthe upper portion of the` mould isin a plurality 'of sections divided vertically and arranged to beadvanced into place above the bottom section of the mould from oppositesides ot the axis thereof.

ERNEST FRASER JONES. u

